What Is the Model Context Protocol (MCP)?
Last updated 2026-09-14
Quick answer
The Model Context Protocol (MCP) is an open standard that lets AI assistants talk to external tools and data sources through one consistent interface. Instead of building a bespoke integration for every app, developers expose capabilities as MCP servers and any MCP-compatible client — Claude, Cursor, VS Code, ChatGPT-compatible agents and more — can use them.
The core idea
Before MCP, every AI tool needed its own connectors. MCP standardises the connection: a client speaks the protocol, a server exposes tools (actions), resources (data) and prompts (templates), and the two exchange structured JSON messages.
Think of MCP as USB-C for AI tools. One port, many devices. A single filesystem server works with any client that speaks MCP, and a single client can load dozens of servers at once.
Clients, servers and transports
Three pieces make up an MCP setup:
- ▸Client / host — the AI app you use (Claude Desktop, Cursor, VS Code, Windsurf, a custom agent). It discovers servers and decides which tools to call.
- ▸Server — a small program that exposes tools and data. It can run locally (stdio) or remotely (HTTP/SSE).
- ▸Transport — how they talk. stdio runs a local process; Streamable HTTP and SSE connect to remote servers over the network.
What MCP servers can do
Servers commonly wrap databases, file systems, browsers, SaaS APIs (Slack, Notion, Stripe), search engines and cloud platforms. Because the interface is standardised, the same request — 'search my repo for open issues' — works the same way regardless of the underlying service.
Why it matters for SEO and AI search
MCP is how agents get grounded, up-to-date context. When an AI answer cites a tool, it is often because an MCP server supplied the data. That makes MCP tooling a fast-growing category with real, verifiable demand.
Frequently asked questions
Is MCP free to use?＋
Yes. MCP is an open protocol published by Anthropic under an MIT license. You can build and run servers for free; individual servers may wrap paid APIs like Brave Search or Google Maps.
Which AI apps support MCP?＋
Claude Desktop, Claude Code, Cursor, VS Code (GitHub Copilot), Windsurf, Zed, Cline, Continue and many agent frameworks support MCP. Support is expanding quickly.
Do I need to write code to use MCP?＋
No. For most servers you paste a short JSON config into your client and it runs. Building your own server does require code.
What is the difference between MCP and a plugin or function call?＋
Function calling is a model-level feature tied to one API. MCP is a transport-level standard that any client or server can implement, so a single server works across many apps.